NEVER add ignore packages until you know what it does, you now have an unbootable system, nvidia modules need to be build on the exact kernel you run. The safeguard to make nvidia depend on exact kernel versions is added precisely to avoid this kind of breakage, make it impossible to update when kernel & nvidia don't match.
Make sure to update with either
upd or open octopi. See if your mirror is synced. If not wait until it is synced, if that takes more then a day, report which mirror you use.
If your mirror is synced it will pull in the correct nvidia-340xx version.